Holloway played Sawyer on the hit ABC series and while no one knows who the actor might play in a Marvel film (or even which Marvel film he might star in), speculation is running rampant. AvengersNews lists three possibilities -- two that seem potentially interesting, one that leaves me feeling "Meh."
The first theory is that Holloway will tackle the role of Henry Pym, better known as Ant-Man, in the upcoming Avengers film and then star as the character in a planned spin-off. I'm okay with that casting. I remain unconvinced that there should even be a standalone Ant-Man movie, but maybe Holloway in a starring role could give the character the push he needs to become more recognizable outside of comic shops.
Other rumors seem to be pointing toward the actor playing Clint Barton, aka Hawkeye. This would also put him in The Avengers and maybe a spin-off or sequel down the line. Hawkeye's the role I think Holloway would be best in, but I don't know that Marvel's really committed to doing anything with the character outside of The Avengers.
Finally, some theories point to Holloway playing Timothy "Dum Dum" Dugan, which would again have him in The Avengers and provide him with a lead role in the S.H.I.E.L.D. standalone film. For me, this isn't very exciting.
Of course, none of this may pan out. Holloway hasn't officially signed yet, and even when he does, Marvel might have other plans in store for him. Who could you see Holloway playing? Take on the role of Marvel casting director in the comments section.